


Natural Selection

by manic_intent



Category: X-Men: First Class (2011) - Fandom
Genre: Alternate Universe - Sentinels & Guides, Alternate Universe - Sentinels and Guides Are Known, M/M, That Sentinel/Guide AU where Charles is a Guide and Erik is a Sentinel, and people only develop mutant powers when they meet their guide/sentinel, awkward first meetings
Language: English
Status: Completed
Published: 2014-05-31
Updated: 2014-05-31
Packaged: 2018-01-27 18:26:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,055
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1719080
Author URL: https://archiveofourown.org/users/manic_intent/pseuds/manic_intent
Summary: <blockquote class="userstuff">
              <p>Professor Charles Xavier is thirty-two years old when he meets his Sentinel, and as a credit to his half of the subspecies, he still manages to finish the seminar, run through a credible Q&A session, thank the Dean for the invitation to lecture as a guest at the Yale School of Medicine, before finally fleeing the theatre to find the nearest bathroom. </p><p>While he's busy throwing up into a toilet, he dimly hears the door to the bathrooms opening, then getting locked, and then someone is awkwardly patting him on the back, and Charles <i>knows</i> rather than sees that the Sentinel is conscientiously offering him tissues to wipe his mouth.</p><p>Maybe not a bastard, then.</p>
            </blockquote>





	Natural Selection

**Author's Note:**

> Written for @chessonthebeach on twitter, who asked for a Sentinels&Guides fusion. 
> 
> Okay... I was originally gonna go with the Sentinel/Guide headcanon I wrote for the Person of Interest fic 'Prime Numbers', but that has spirit animals, and I'm aware that Erik's spirit animal (fanon) is a shark... so that wouldn't work. Uhh. So here's a totally separate concept. 
> 
> Note: I've never watched the Sentinel TV show, and I don't usually read Sentinel/Guide fanfic (I always thought it was a crossover with some young adult fiction or something that I've never heard of, until I actually had to write the PoI prompt). :3 So... enjoy?
> 
> \--
> 
> To clarify: All Guides develop telepathic links - but only with their Sentinels. All Sentinels develop Gifts (anything from flight, pyro, etc etc, the usual mutant powers)

I.

Professor Charles Xavier is thirty-two years old when he meets his Sentinel, and as a credit to his half of the subspecies, he still manages to finish the seminar, run through a credible Q&A session, thank the Dean for the invitation to lecture as a guest at the Yale School of Medicine, before finally fleeing the theatre to find the nearest bathroom.

While he's busy throwing up into a toilet, he dimly hears the door to the bathrooms opening, then getting locked, and then someone is awkwardly patting him on the back, and Charles _knows_ rather than sees that the Sentinel is conscientiously offering him tissues to wipe his mouth.

Maybe not a bastard, then. 

Still. Charles empties his stomach, dry heaves, wipes his mouth, flushes, and stalks over to the sink to wash his face, shaking. Perception slips and wavers into two separate skids as he closes his eyes: his own enforced blindness, and the Sentinel's vision, scanning the bathroom before coming up to stand beside him, and there's another awful jolt of vertigo that comes as the Sentinel looks briefly up at himself in the bathroom mirrors. 

At least his Sentinel is handsome as a fucking picture. Movie star handsome, at that, the sort of handsome that didn't usually find its comfortable way into one of Charles' highly specific genetic theory lectures: he's rather used to pale, slightly flabby or stick thin, gawkish and spotty young men, the youthful vanguard of the next generation intelligentsia. _Not_ tall, dark and handsome. 

"Are you all right?" the Sentinel asks, and his voice is accented. Germanic, perhaps: it suits his features - he's tall, dark-haired, with steely eyes, broad-shouldered and lean but muscular. Charles, on the other hand, had been rather looking forward to developing the respectable beard and paunch of his other, older, Oxfordian colleagues. 

"Does it look like I'm all right?" Charles asks, incredulous, and braces himself against the sink, trying to breathe slowly through his mouth. 

"You finished the lecture," the Sentinel points out mildly, though his lips quirk. "I thought perhaps that the bond had no side effects."

"I've worked far too hard to _get_ this speaker invite," Charles retorts, and then he sighs, and barks out a short laugh. "Seeing as we're going to have to get _registered_ tomorrow, I thought that I might as well tick _something_ off my bucket list."

The Sentinel narrows his eyes. "Registered?"

"At Interpol? Like all Sentinel and Guide pairs?" Charles washes his mouth out, then his hands, dries them off, then squares his shoulders and turns with a sigh, stretching out a palm. "Charles Xavier. But you probably knew that, seeing as my name was on the signage outside the lecture theatre." 

" _Professor_ Charles Xavier," the Sentinel corrects, with another quick, sharp smile, and shakes Charles' hand. "Erik Lehnsherr." 

"Are you a student here, Erik?" Charles asks, and he _hears_ the negative in Erik's mind even as Erik shakes his head. "What in the blazes were you doing in my lecture, then? Do you attend experimental genetics presentations for fun?" Admittedly, that would be kind of hot.

"I was looking for someone," Erik says evasively, even as a name and a face surfaces in his mind, and Charles wrinkles his brow.

"Shaw? Who on earth is Shaw?" 

"Someone with an... interest in Sentinel-Guide biochemistry. Unfortunately, he did not attend the lecture as I thought he would," Erik supplies, even as he narrows his eyes. "Your Guide telepathic link is going to take some getting used to."

"Yes, I happen to be rather an _expert_ on its current state as a problem, thank you, my vision keeps shunting off into yours, and that's what's been giving me the most terrible vertigo." Charles takes in a deep, slow breath. He's starting to understand how to keep just within his own mind, but it takes concentration. "What powers did _you_ get?" 

"I can sense metal," Erik says doubtfully. "Perhaps I can affect it, but I'm not sure. You turned rather pale on stage when I tried it on a pen, so I stopped."

"Great," Charles sighs. "My life has been ruined just so that someone can become a giant natural _magnet_. Couldn't you have developed flight, perhaps, or control over fire? Or shapeshifting?" 

Erik frowns at him, and temper spikes briefly in his mind, making Charles stumble, dizzy, before settling as Erik hastily grasps for his elbow to steady him. "Why do we have to register at Interpol?"

"I've already mentioned-" He feels Erik's impatience as a static buzz, and Charles adds, "Because we're now dangerous, I presume, though I'm not entirely certain how dangerous a walking magnet might be. I've never been particularly interested in the legal side of things, only the scientific aspect of the Sentinel-Guide bond. For example, um, maybe you'll be dangerous around certain machinery, or shouldn't be let near people with pacemakers-"

"Charles," Erik says softly. "We are _not_ going to register at Interpol."

Charles frowns at Erik. "We have to. That's what all Guides and Sentinels do when they pair up. We have to go on the register-"

"We're not registering at Interpol," Erik cuts in evenly, "Because I'm already _wanted_ by Interpol." 

This is Charles' life, apparently. He should have expected it. 

"You're a _criminal?_ "

Erik rolls his eyes. "Say it more loudly, why don't you?" 

"How in the world did you get wanted by _Interpol_?" Charles demands. "Are you a drug trafficker? A weapons dealer? An art thief? A terrorist?"

"Slow down," Erik says, looking amused. "Let's go somewhere more private, and I'll tell you about it."

"I am _not_ going anywhere with an international criminal," Charles growls.

"Yes you are," Erik retorts, "Or I'm going to drag you out of here, _through_ this University, and you can deal with having to explain matters to the Dean, and campus security." 

"If it's possible to get on the Interpol wanted list for being a right arsehole," Charles says resentfully, "Then you don't need to explain the matter further."

II.

Erik drives, because Charles didn't rent a car and because he starts to feel ill again the moment Erik pulls out into traffic. Scrolling down the window and taking deep breaths helps, and he's almost human again by the time Erik pulls up in the decidedly ratty parking lot of a dilapidated motel.

"Good gracious," Charles says, aghast. "Couldn't we go to _my_ hotel?"

"No," Erik smirks again. "We can't risk anyone looking for us." 

"Christ," Charles mutters, pinching at the ridge of his nose, "I have _luggage_ in my hotel room. A draft of my _thesis_. Notes and research. I can't just abandon that."

"You might have to," Erik points out blithely. "We may have to leave the country. Now get out of the car and come nicely."

Irritated, Charles complies, following Erik up the rather dank and strange-smelling stairway to the second floor open corridor of the motel. He loses sight of Erik briefly, as the stairwell curls along the building facade, and Charles finds himself hastily scrambling up the stairs at the sudden drop in his stomach, the sense of everything being _wrong_. Charles nearly barrels straight into Erik, who had paused, possibly sensing his distress, and Erik presses a palm against his back, settling him down.

It's an entirely awkward way to be led into someone's _motel_ room, and Charles is irritated and resentful again by the time Erik locks the door behind them. He sits down on a wooden chair, the only piece of furniture in the room that seems definitely clean, and folds his hands in his lap, looking around the tiny room. There's a distinct, chemical smell, like very cheap air freshener, and while the bed is made, the graying carpet is sparse, and the bathroom is in an alarming shade of powder blue. 

"So," Erik sits down on the bed, facing him. "This was unexpected."

"Yes, thank you, I gathered as much," Charles shoots back.

"For someone who spent years researching the Sentinel-Guide gene sequencing," Erik says dryly, "You're not taking this very well."

"I didn't exactly expect it to happen, did I? It's a rather _rare_ phenomenon. Besides, Sentinel-Guide pairs almost always end up working as government operatives of some sort," Charles points out irritably. "Seeing as it follows the Guide's nationality, traditionally, I suppose that we would've ended up in MI6, or such, which isn't particularly conducive to being a tenured Professor. That would have been bad enough. But since you've just told me that you're a _criminal_..."

"I see," Erik shrugs. "But that aside, shouldn't this be fascinating to you? You're experiencing accelerated mutation firsthand." 

"Latent triggered acceleration," Charles corrects absently, then frowns. "Well _yes_ , I suppose if we didn't have to register _and_ if you weren't some sort of international criminal then this would be _utterly fascinating_." 

"There you go," Erik says reassuringly. "I have no intention of registering. That means that _you_ don't have to register. You can keep doing what you like. Once the bond settles down, _I_ will keep doing what I like. Does that sound good?"

"Doing what you like?" Charles asks, suspicious, and hazards a guess, "Buying and selling weapons?" Erik looks like the sort.

"That's not what I do," Erik says, amused. "But if you really must know, I hunt and kill Nazi war criminals." 

"... All right," Charles says faintly, sounding strangled, "If that's true, I suppose that it's not as bad as drug trafficking. Shouldn't Interpol _hire_ you rather than hunt you?"

"Many of these criminals became rich during the war, and made deals," Erik shrugs. "Besides, I have no patience for the International Court of Justice. Are we agreed? We just have to live with each other for perhaps a month or two, and then we can go our separate ways."

"That's not how the bond works," Charles tells Erik, uncomfortably. "You're going to need me around to control and develop your powers. There's a trade-off. Brain chemistry."

"Supposedly," Erik narrows his eyes, "You're the world's leading expert on the genetics of Sentinel-Guide mutations. I'm sure that you can figure something out in the next two months. I don't want to have to drag someone like you around while I'm hunting dangerous people."

"Someone like _me_?" Charles snaps, outraged.

"Yes, _you_ ," Erik snarls, "I _know_ about you, I researched you before entering that lecture, in case you turned out to be one of Shaw's associates. You've always been spoiled. You're vastly rich, you're arrogant, self-absorbed, and-" _I want to fuck you into this bed._ "Self-entitled!" 

"What?" Charles blinks, his indignation derailed, and Erik stares at him for a long, furious moment before he realizes what happened. He looks embarrassed only for a moment, before his smirk turns challenging, and Charles growls as he pushes himself out of the hair and grabs Erik by the lapels of his shirt, dragging him up for a rough kiss. 

This isn't an unusual development of the Sentinel-Guide bond, Charles recalls, as Erik fumbles with his ascot and suit, dumping Charles' tailored clothes onto the ground and ignoring Charles' squawk of outrage. He bites Erik during the next kiss but Erik merely growls and twists them around, all but bouncing Charles onto his back on the rough sheets. "Oh _no_ you don't," Charles hisses, slapping away Erik's hands as he catches an image of Erik ripping open his shirt, and Erik rolls his eyes and works on his own clothes as Erik gets his shirt off, then his belt. 

They kick off shoes, drag off trousers and boxers and the rest and end up wrestling briefly on the bed before they get a proper fit, kissing and rubbing against each other with uncontrolled eagerness. Charles reaches down, grabbing them both; it's too dry and rough, but Erik groans anyway and thrusts so hard against his grip that his fingers slip and Erik's impressively _large_ cock drags briefly up against his belly. God, but Erik is all hard muscle, biting down hard on Charles' neck and snarling as Charles hisses and digs the nails of his other hand hard into Erik's back. 

"Lube," Charles manages to gasp out, and when Erik merely growls and sucks another mark onto Charles neck, he hisses and slaps at Erik's back. "You _do_ have lube, don't you? I'm not about to take that monster you have between your legs without help!"

Erik rears back, shooting Charles an irritated glance before reaching over for the side drawer, dragging it out impatiently. The lamp sitting on the side table hums and jumps as he touches the drawer, and Charles stares, momentarily distracted, but then Erik uncaps the discreet tube, spilling some of it over his fingers and Charles' shoulder in his haste. The lube is cold, as Erik presses his fingers between Charles' legs, but Charles doesn't care, spreading his thighs and arching his back when Erik presses in a finger, brutal and a little too quick. 

"Bastard," Charles hisses, as Erik doesn't wait particularly long before forcing in another finger, sinking his teeth again into Charles' neck. Annoyed, Charles drags his fingers through Erik's sleek hair and flings sensation down the shaky loop that he feels between them, and laughs as Erik stiffens and nearly fumbles the lube. The bite against his neck turns into a lick, then Erik presses a gentler kiss against Charles' lips, or tries to - Charles merely bites down again. "I didn't say slow down," he retorts, and Erik smirks at him even as he starts to scissor his fingers, angling for Charles' prostate.

When he finds it, Charles bucks against him and squeals, and Erik bares far too many teeth as he nips down Charles' chest, worrying at one nipple, tonguing it until Charles squirms and then biting until Charles tugs at his hair with a yelp. Charles is panting and groaning by the time Erik gets to three fingers, his knees pressing urgently up against Erik's waist as Erik struggles with a condom, his fingers jerky with impatience, then lines himself up, stroking the head of his cock teasingly from Charles' perineum down to his arse and back up.

" _Erik_ ," Charles growls, and Erik snorts and pushes in, a gritty, brutal slide, pinning Charles under him by bracing one hand on Charles' shoulder and splaying the other under the small of Charles' back, lifting him with shocking ease onto Erik's cock. Charles is breathless by the time Erik bottoms out, gasping and making wet, incoherent noises that Erik clearly likes, judging by the sudden rush of lust that he feels from Erik's mind, a bright, hot surge of pure emotion. 

It's like nothing that Charles has ever felt, not like this, distilled down and brilliantly unselfconscious. Charles clings to Erik, dizzy with it, choking out a laugh as he feels Erik thrust into him, still far too large, far too quick to be entirely comfortable but he digs his heels into Erik's back and urges him on. The headboard rattles and slams into the wall as Erik growls and obliges, dragging a pillow under Charles' hips as he takes him, shifting until the thick head of his cock skitters against the _perfect_ spot again and makes Charles shout. 

"Keep it _down_ ," someone yells from the other room, muffled and indignant, and Charles starts to laugh, part shocked, part exhilarated, and Erik growls and starts to cover Charles' shoulders with bites that'll bruise in a few hours. When Erik gets a hand on Charles' cock and strokes, it doesn't take Charles long to come, spilling in thick stripes over Erik's long fingers. Erik grunts, shifting both his hands to Charles' hips, and his thrusts get deeper, harder, something shrieks and groans from the room around them, like metal straining, then Erik lets out a harsh gasp as he comes, digging his fingers roughly into Charles' flesh, marking him. 

As Erik pulls out gingerly and settles down, he abruptly starts to laugh, breathless, rueful, and Charles frowns before he pushes himself up on his elbows to survey the damage. Almost all the metal fittings that he can see in the room seem half-melted, and some are utterly unrecognisable - the drawer handles are shiny molten stains on the worn wood, the bars on the small cot of a bed are gone, as are the knobs to the bathroom door and the tap. He groans, lying back down on the bed. "So much for hiding."

"I'll pay for the damage and think of something," Erik shrugs, as he gets up to tie off the condom and dispose of it before coming back to the bed. "Clearly, I'm also not _just_ a magnet." 

"Don't be so smug. You're a magnet for bloody _trouble_ , that's what you are," Charles growls, but he lets Erik settle close and throw an arm over his waist. "And I still want my luggage," he adds.

"Mm," Erik frowns a little. "I suppose if we're going to pretend that nothing happened, you should check out of your hotel and return to England normally." 

"And how am I meant to explain your presence?" 

"Lover?" Erik says teasingly, and as Charles rolls his eyes, adds, "Research assistant? Bodyguard?"

"I already have research assistants. And a bodyguard will just look most terribly out of place." Charles frowns at Erik. "Long lost relative?"

"How is _that_ going to be remotely feasible?"

"Secretary," Charles decides, and smirks as Erik rolls his eyes. "Personal assistant." 

"Is _that_ what they call 'lover' over in Oxford?" Erik drawls, but he rolls on top to take a sloppy, hungry kiss, ignoring how Charles shoves at him, and eventually, Charles settles down, drinking in the satisfaction in Erik's mind, the warmth, the solace. Erik has been alone for a long time, Charles realizes, all at once. And so has Charles himself. Maybe this could work out-

"So," Erik says conversationally, as they part, "You're a tenured Professor." Charles nods. "Maybe you could take leave every few months or so whenever I get a lead on someone on my list. Or Shaw."

"And go around helping you gad about the world, murdering people? Absolutely _not_ ," Charles retorts incredulously, and Erik rolls his eyes and nips Charles hard on his ear, ignoring Charles' yelp of outrage. 

No. They definitely _were_ going to be the death of each other.

**Author's Note:**

> Thanks for reading! ;3 I'm on tumblr as manic-intent, and twitter as @manic_intent - happy to discuss ficbunnies and random things.


End file.
